Republic of Korea Patent No. 10-0778089 discloses an exploration system and method for acquiring the field configured network information of an underground low voltage (LV) distribution system, particularly in urban areas where multiple transformers are grouped in a same location, including a plurality of master devices, a slave device and a detecting device. The plurality of master devices are connected to the terminals of phases and earth inside of each of the transformers to broadcast the unique identification codes of a transformer, a phase and a circuit over the feeding electric lines, the slave device acquires the information of a source transformer, a connected phase and a circuit by reading the codes in the broadcast or requests reply from the connecting point of an electric line at a service entrance to a customer premise, and the detecting device acquires the information of the source transformer, a phase and a customer by collecting a signal transmitted by the slave device in the middle of the laying path of the electric line without removing the insulation while in service.
Republic of Korea Patent No. 10-0816101 relates to an earth voltage leakage sensing device and discloses the arrangement of a transmitting device and a receiving device to perform the task in service. While the transmitting device applies a chain of asymmetrical pulse signals to a pad mounted transformer, a stream of output signals fed by the transformer to feeder cables are mixed signals of AC mains and asymmetrical pulse AC signals. The receiving device includes a signal input part for gathering the earth voltage signals from the ground, a filtering part to eliminate the symmetrical voltage of AC mains and noises from the signal inputs, a comparator part to compare the DC signal polarity to display the + or − of the signal from the filtering part, and an averaging part to average the value of accumulated DC signal value from the filtering part in the specific period to display the signal value with the polarity from the comparator part, and picks the asymmetrical pulse signal from the earth after removing the commercial AC voltage wave from the detectable composite signal at the leaking point.
Republic of Korea Patent No. 10-0966759 relates to a method for detecting and repairing a comprehensive streetlight power system including a power cable from a utility and power distribution system to each streetlight pole. The method includes performing an electric leakage diagnosis by measuring a resistive and capacitive leakage current value under no load and full load conditions at a location where cables stretched down from the utility pole run into a protective pipe for protecting the cables to determine whether an electric leakage occurs in a street light power system when the resistive and capacitive leakage current values are exceeding a threshold level, tracing an underground cable from the utility pole to measure an electromagnetic flux over the ground by increasing the sensitivity by step to detect an earth leaking point, and marking an earth leaking point by recording distances from landmarks.
In addition to above prior patents, New Technology #56 granted by MOKE (Ministry of Knowledge Economy) of Republic of Korea may be referenced as a non-patent document (http://www.electricity.or.kr/ntep/search/search_view).